The fines relate to the initial part of the investigation into whether manufacturers made cartel agreements on the supply of rail to Germany's Deutsche Bahn, to the disadvantage of the railway company. The fines aren't legally binding and may be appealed.

"This case shows anew that public tenders require strong scrutiny," the office said in a statement.

In a statement, voestalpine said its fine would have been several times higher without its prompt cooperation in the probe.

ThyssenKrupp said it would accept the fine to settle this part of the case, and that investigations are still underway regarding two other product areas. The company has made a provision of EUR30 million for the remainder of the probe, it said in a statement.

The cartel office said it would expand the investigation to other areas, including the supply of rail to regional and local railways.